The entire collection of responses is stored in the data column of the entity that extends
AbstractResponseData. This data array is stored as a json serialized array. By default, the data is stored in
whatever format the FormType returns. In most situations, this is sufficient. I.e. a TextType response is stored as a
simple string field, multiple ChoiceType is stored as an array, DateType is stored as a serialized Date object.
The storage of values therefore can be altered by customizing your application's formTypes and utilizing DataMappers
or DataTransformers as appropriate for your business logic.
ChoiceTypeTransformed will store the value of the selected choice(s). If multiple values are allowed, they are stored as a comma-seperated string. If the label for the value is required, the application should employ an Enum or other type of associating the value to the label.
ChoiceWithOtherType will store the _value_of the selected choice(s), or the indicated 'other' value (or all of the above) the same as ChoiceTypeTransformed, above.